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moodle/lib/filterlib.php

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<?php
// This file is part of Moodle - http://moodle.org/
//
// Moodle is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// Moodle is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with Moodle. If not, see <http://www.gnu.org/licenses/>.
/**
* Library functions for managing text filter plugins.
*
* @package core
* @subpackage filter
* @copyright 1999 onwards Martin Dougiamas {@link http://moodle.com}
* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
*/
defined('MOODLE_INTERNAL') || die();
/** The states a filter can be in, stored in the filter_active table. */
define('TEXTFILTER_ON', 1);
/** The states a filter can be in, stored in the filter_active table. */
define('TEXTFILTER_INHERIT', 0);
/** The states a filter can be in, stored in the filter_active table. */
define('TEXTFILTER_OFF', -1);
/** The states a filter can be in, stored in the filter_active table. */
define('TEXTFILTER_DISABLED', -9999);
/**
* Define one exclusive separator that we'll use in the temp saved tags
* keys. It must be something rare enough to avoid having matches with
* filterobjects. MDL-18165
*/
define('TEXTFILTER_EXCL_SEPARATOR', '-%-');
/**
* Class to manage the filtering of strings. It is intended that this class is
* only used by weblib.php. Client code should probably be using the
* format_text and format_string functions.
*
* This class is a singleton.
*
* @package core
* @subpackage filter
* @copyright 1999 onwards Martin Dougiamas {@link http://moodle.com}
* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
*/
class filter_manager {
/**
* @var array This list of active filters, by context, for filtering content.
* An array contextid => array of filter objects.
*/
protected $textfilters = array();
/**
* @var array This list of active filters, by context, for filtering strings.
* An array contextid => array of filter objects.
*/
protected $stringfilters = array();
/** @var array Exploded version of $CFG->stringfilters. */
protected $stringfilternames = array();
/** @var object Holds the singleton instance. */
protected static $singletoninstance;
protected function __construct() {
$this->stringfilternames = filter_get_string_filters();
}
/**
* @return filter_manager the singleton instance.
*/
public static function instance() {
global $CFG;
if (is_null(self::$singletoninstance)) {
if (!empty($CFG->perfdebug)) {
self::$singletoninstance = new performance_measuring_filter_manager();
} else {
self::$singletoninstance = new self();
}
}
return self::$singletoninstance;
}
/**
* Load all the filters required by this context.
*
* @param object $context
*/
protected function load_filters($context) {
$filters = filter_get_active_in_context($context);
$this->textfilters[$context->id] = array();
$this->stringfilters[$context->id] = array();
foreach ($filters as $filtername => $localconfig) {
$filter = $this->make_filter_object($filtername, $context, $localconfig);
if (is_null($filter)) {
continue;
}
$this->textfilters[$context->id][] = $filter;
if (in_array($filtername, $this->stringfilternames)) {
$this->stringfilters[$context->id][] = $filter;
}
}
}
/**
* Factory method for creating a filter
*
* @param string $filter The filter name, for example 'filter/tex' or 'mod/glossary'.
* @param object $context context object.
* @param array $localconfig array of local configuration variables for this filter.
* @return object moodle_text_filter The filter, or null, if this type of filter is
* not recognised or could not be created.
*/
protected function make_filter_object($filtername, $context, $localconfig) {
global $CFG;
$path = $CFG->dirroot .'/'. $filtername .'/filter.php';
if (!is_readable($path)) {
return null;
}
include_once($path);
$filterclassname = 'filter_' . basename($filtername);
if (class_exists($filterclassname)) {
return new $filterclassname($context, $localconfig);
}
$legacyfunctionname = basename($filtername) . '_filter';
if (function_exists($legacyfunctionname)) {
return new legacy_filter($legacyfunctionname, $context, $localconfig);
}
return null;
}
/**
* @todo Document this function
* @param string $text
* @param array $filterchain
* @return string $text
*/
protected function apply_filter_chain($text, $filterchain) {
foreach ($filterchain as $filter) {
$text = $filter->filter($text);
}
return $text;
}
/**
* @todo Document this function
* @param object $context
* @return object A text filter
*/
protected function get_text_filters($context) {
if (!isset($this->textfilters[$context->id])) {
$this->load_filters($context);
}
return $this->textfilters[$context->id];
}
/**
* @todo Document this function
* @param object $context
* @return object A string filter
*/
protected function get_string_filters($context) {
if (!isset($this->stringfilters[$context->id])) {
$this->load_filters($context);
}
return $this->stringfilters[$context->id];
}
/**
* Filter some text
*
* @param string $text The text to filter
* @param object $context
* @return string resulting text
*/
public function filter_text($text, $context) {
$text = $this->apply_filter_chain($text, $this->get_text_filters($context));
/// <nolink> tags removed for XHTML compatibility
$text = str_replace(array('<nolink>', '</nolink>'), '', $text);
return $text;
}
/**
* Filter a piece of string
*
* @param string $string The text to filter
* @param object $context
* @return string resulting string
*/
public function filter_string($string, $context) {
return $this->apply_filter_chain($string, $this->get_string_filters($context));
}
/**
* @todo Document this function
* @param object $context
* @return object A string filter
*/
public function text_filtering_hash($context) {
$filters = $this->get_text_filters($context);
$hashes = array();
foreach ($filters as $filter) {
$hashes[] = $filter->hash();
}
return implode('-', $hashes);
}
}
/**
* Filter manager subclass that does nothing. Having this simplifies the logic
* of format_text, etc.
*
* @todo Document this class
*
* @package core
* @subpackage filter
* @copyright 1999 onwards Martin Dougiamas {@link http://moodle.com}
* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
*/
class null_filter_manager {
/**
* @return string
*/
public function filter_text($text, $context) {
return $text;
}
/**
* @return string
*/
public function filter_string($string, $context) {
return $string;
}
/**
* @return string
*/
public function text_filtering_hash() {
return '';
}
}
/**
* Filter manager subclass that tacks how much work it does.
*
* @todo Document this class
*
* @package core
* @subpackage filter
* @copyright 1999 onwards Martin Dougiamas {@link http://moodle.com}
* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
*/
class performance_measuring_filter_manager extends filter_manager {
/** @var int */
protected $filterscreated = 0;
protected $textsfiltered = 0;
protected $stringsfiltered = 0;
/**
* @param string $filtername
* @param object $context
* @param mixed $localconfig
* @return mixed
*/
protected function make_filter_object($filtername, $context, $localconfig) {
$this->filterscreated++;
return parent::make_filter_object($filtername, $context, $localconfig);
}
/**
* @param string $text
* @param object $context
* @return mixed
*/
public function filter_text($text, $context) {
$this->textsfiltered++;
return parent::filter_text($text, $context);
}
/**
* @param string $string
* @param object $context
* @return mixed
*/
public function filter_string($string, $context) {
$this->stringsfiltered++;
return parent::filter_string($string, $context);
}
/**
* @return array
*/
public function get_performance_summary() {
return array(array(
'contextswithfilters' => count($this->textfilters),
'filterscreated' => $this->filterscreated,
'textsfiltered' => $this->textsfiltered,
'stringsfiltered' => $this->stringsfiltered,
), array(
'contextswithfilters' => 'Contexts for which filters were loaded',
'filterscreated' => 'Filters created',
'textsfiltered' => 'Pieces of content filtered',
'stringsfiltered' => 'Strings filtered',
));
}
}
/**
* Base class for text filters. You just need to override this class and
* implement the filter method.
*
* @package core
* @subpackage filter
* @copyright 1999 onwards Martin Dougiamas {@link http://moodle.com}
* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
*/
abstract class moodle_text_filter {
/** @var object The context we are in. */
protected $context;
/** @var object Any local configuration for this filter in this context. */
protected $localconfig;
/**
* Set any context-specific configuration for this filter.
* @param object $context The current course id.
* @param object $context The current context.
* @param array $config Any context-specific configuration for this filter.
*/
public function __construct($context, array $localconfig) {
$this->context = $context;
$this->localconfig = $localconfig;
}
/**
* @return string The class name of the current class
*/
public function hash() {
return __CLASS__;
}
/**
* Override this function to actually implement the filtering.
*
* @param $text some HTML content.
* @return the HTML content after the filtering has been applied.
*/
public abstract function filter($text);
}
/**
* moodle_text_filter implementation that encapsulates an old-style filter that
* only defines a function, not a class.
*
* @package core
* @subpackage filter
* @copyright 1999 onwards Martin Dougiamas {@link http://moodle.com}
* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
*/
class legacy_filter extends moodle_text_filter {
/** @var string */
protected $filterfunction;
protected $courseid;
/**
* Set any context-specific configuration for this filter.
*
* @param string $filterfunction
* @param object $context The current context.
* @param array $config Any context-specific configuration for this filter.
*/
public function __construct($filterfunction, $context, array $localconfig) {
parent::__construct($context, $localconfig);
$this->filterfunction = $filterfunction;
$this->courseid = get_courseid_from_context($this->context);
}
/**
* @param string $text
* @return mixed
*/
public function filter($text) {
if ($this->courseid) {
// old filters are called only when inside courses
return call_user_func($this->filterfunction, $this->courseid, $text);
} else {
return $text;
}
}
}
/**
* This is just a little object to define a phrase and some instructions
* for how to process it. Filters can create an array of these to pass
* to the filter_phrases function below.
*
* @package core
* @subpackage filter
* @copyright 1999 onwards Martin Dougiamas {@link http://moodle.com}
* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
**/
class filterobject {
/** @var string */
var $phrase;
var $hreftagbegin;
var $hreftagend;
/** @var bool */
var $casesensitive;
var $fullmatch;
/** @var mixed */
var $replacementphrase;
var $work_phrase;
var $work_hreftagbegin;
var $work_hreftagend;
var $work_casesensitive;
var $work_fullmatch;
var $work_replacementphrase;
/** @var bool */
var $work_calculated;
/**
* A constructor just because I like constructing
*
* @param string $phrase
* @param string $hreftagbegin
* @param string $hreftagend
* @param bool $casesensitive
* @param bool $fullmatch
* @param mixed $replacementphrase
*/
function filterobject($phrase, $hreftagbegin = '<span class="highlight">',
$hreftagend = '</span>',
$casesensitive = false,
$fullmatch = false,
$replacementphrase = NULL) {
$this->phrase = $phrase;
$this->hreftagbegin = $hreftagbegin;
$this->hreftagend = $hreftagend;
$this->casesensitive = $casesensitive;
$this->fullmatch = $fullmatch;
$this->replacementphrase= $replacementphrase;
$this->work_calculated = false;
}
}
/**
* Look up the name of this filter in the most appropriate location.
* If $filterlocation = 'mod' then does get_string('filtername', $filter);
* else if $filterlocation = 'filter' then does get_string('filtername', 'filter_' . $filter);
* with a fallback to get_string('filtername', $filter) for backwards compatibility.
* These are the only two options supported at the moment.
*
* @param string $filter the folder name where the filter lives.
* @return string the human-readable name for this filter.
*/
function filter_get_name($filter) {
list($type, $filter) = explode('/', $filter);
switch ($type) {
case 'filter':
$strfiltername = get_string('filtername', 'filter_' . $filter);
if (substr($strfiltername, 0, 2) != '[[') {
// found a valid string.
return $strfiltername;
}
// Fall through to try the legacy location.
case 'mod':
$strfiltername = get_string('filtername', $filter);
if (substr($strfiltername, 0, 2) == '[[') {
$strfiltername .= ' (' . $type . '/' . $filter . ')';
}
return $strfiltername;
default:
throw new coding_exception('Unknown filter type ' . $type);
}
}
/**
* Get the names of all the filters installed in this Moodle.
*
* @global object
* @return array path => filter name from the appropriate lang file. e.g.
* array('mod/glossary' => 'Glossary Auto-linking', 'filter/tex' => 'TeX Notation');
* sorted in alphabetical order of name.
*/
function filter_get_all_installed() {
global $CFG;
$filternames = array();
$filterlocations = array('mod', 'filter');
foreach ($filterlocations as $filterlocation) {
$filters = get_list_of_plugins($filterlocation);
foreach ($filters as $filter) {
$path = $filterlocation . '/' . $filter;
if (is_readable($CFG->dirroot . '/' . $path . '/filter.php')) {
$strfiltername = filter_get_name($path);
$filternames[$path] = $strfiltername;
}
}
}
asort($filternames, SORT_LOCALE_STRING);
return $filternames;
}
/**
* Set the global activated state for a text filter.
*
* @global object
* @param string $filter The filter name, for example 'filter/tex' or 'mod/glossary'.
* @param integer $state One of the values TEXTFILTER_ON, TEXTFILTER_OFF or TEXTFILTER_DISABLED.
* @param integer $sortorder (optional) a position in the sortorder to place this filter.
* If not given defaults to:
* No change in order if we are updating an existing record, and not changing to or from TEXTFILTER_DISABLED.
* Just after the last currently active filter when adding an unknown filter
* in state TEXTFILTER_ON or TEXTFILTER_OFF, or enabling/disabling an existing filter.
* Just after the very last filter when adding an unknown filter in state TEXTFILTER_DISABLED
*/
function filter_set_global_state($filter, $state, $sortorder = false) {
global $DB;
// Check requested state is valid.
if (!in_array($state, array(TEXTFILTER_ON, TEXTFILTER_OFF, TEXTFILTER_DISABLED))) {
throw new coding_exception("Illegal option '$state' passed to filter_set_global_state. " .
"Must be one of TEXTFILTER_ON, TEXTFILTER_OFF or TEXTFILTER_DISABLED.");
}
// Check sortorder is valid.
if ($sortorder !== false) {
if ($sortorder < 1 || $sortorder > $DB->get_field('filter_active', 'MAX(sortorder)', array()) + 1) {
throw new coding_exception("Invalid sort order passed to filter_set_global_state.");
}
}
// See if there is an existing record.
$syscontext = get_context_instance(CONTEXT_SYSTEM);
$rec = $DB->get_record('filter_active', array('filter' => $filter, 'contextid' => $syscontext->id));
if (empty($rec)) {
$insert = true;
$rec = new stdClass;
$rec->filter = $filter;
$rec->contextid = $syscontext->id;
} else {
$insert = false;
if ($sortorder === false && !($rec->active == TEXTFILTER_DISABLED xor $state == TEXTFILTER_DISABLED)) {
$sortorder = $rec->sortorder;
}
}
// Automatic sort order.
if ($sortorder === false) {
if ($state == TEXTFILTER_DISABLED && $insert) {
$prevmaxsortorder = $DB->get_field('filter_active', 'MAX(sortorder)', array());
} else {
$prevmaxsortorder = $DB->get_field_select('filter_active', 'MAX(sortorder)', 'active <> ?', array(TEXTFILTER_DISABLED));
}
if (empty($prevmaxsortorder)) {
$sortorder = 1;
} else {
$sortorder = $prevmaxsortorder + 1;
if (!$insert && $state == TEXTFILTER_DISABLED) {
$sortorder = $prevmaxsortorder;
}
}
}
// Move any existing records out of the way of the sortorder.
if ($insert) {
$DB->execute('UPDATE {filter_active} SET sortorder = sortorder + 1 WHERE sortorder >= ?', array($sortorder));
} else if ($sortorder != $rec->sortorder) {
$sparesortorder = $DB->get_field('filter_active', 'MIN(sortorder)', array()) - 1;
$DB->set_field('filter_active', 'sortorder', $sparesortorder, array('filter' => $filter, 'contextid' => $syscontext->id));
if ($sortorder < $rec->sortorder) {
$DB->execute('UPDATE {filter_active} SET sortorder = sortorder + 1 WHERE sortorder >= ? AND sortorder < ?',
array($sortorder, $rec->sortorder));
} else if ($sortorder > $rec->sortorder) {
$DB->execute('UPDATE {filter_active} SET sortorder = sortorder - 1 WHERE sortorder <= ? AND sortorder > ?',
array($sortorder, $rec->sortorder));
}
}
// Insert/update the new record.
$rec->active = $state;
$rec->sortorder = $sortorder;
if ($insert) {
$DB->insert_record('filter_active', $rec);
} else {
$DB->update_record('filter_active', $rec);
}
}
/**
* @param string $filter The filter name, for example 'filter/tex' or 'mod/glossary'.
* @return boolean is this filter allowed to be used on this site. That is, the
* admin has set the global 'active' setting to On, or Off, but available.
*/
function filter_is_enabled($filter) {
return array_key_exists($filter, filter_get_globally_enabled());
}
/**
* Return a list of all the filters that may be in use somewhere.
*
* @staticvar array $enabledfilters
* @return array where the keys and values are both the filter name, like 'filter/tex'.
*/
function filter_get_globally_enabled() {
static $enabledfilters = null;
if (is_null($enabledfilters)) {
$filters = filter_get_global_states();
$enabledfilters = array();
foreach ($filters as $filter => $filerinfo) {
if ($filerinfo->active != TEXTFILTER_DISABLED) {
$enabledfilters[$filter] = $filter;
}
}
}
return $enabledfilters;
}
/**
* Return the names of the filters that should also be applied to strings
* (when they are enabled).
*
* @global object
* @return array where the keys and values are both the filter name, like 'filter/tex'.
*/
function filter_get_string_filters() {
global $CFG;
$stringfilters = array();
if (!empty($CFG->filterall) && !empty($CFG->stringfilters)) {
$stringfilters = explode(',', $CFG->stringfilters);
$stringfilters = array_combine($stringfilters, $stringfilters);
}
return $stringfilters;
}
/**
* Sets whether a particular active filter should be applied to all strings by
* format_string, or just used by format_text.
*
* @param string $filter The filter name, for example 'filter/tex' or 'mod/glossary'.
* @param boolean $applytostrings if true, this filter will apply to format_string
* and format_text, when it is enabled.
*/
function filter_set_applies_to_strings($filter, $applytostrings) {
$stringfilters = filter_get_string_filters();
$numstringfilters = count($stringfilters);
if ($applytostrings) {
$stringfilters[$filter] = $filter;
} else {
unset($stringfilters[$filter]);
}
if (count($stringfilters) != $numstringfilters) {
set_config('stringfilters', implode(',', $stringfilters));
set_config('filterall', !empty($stringfilters));
}
}
/**
* Set the local activated state for a text filter.
*
* @global object
* @param string $filter The filter name, for example 'filter/tex' or 'mod/glossary'.
* @param integer $contextid The id of the context to get the local config for.
* @param integer $state One of the values TEXTFILTER_ON, TEXTFILTER_OFF or TEXTFILTER_INHERIT.
* @return void
*/
function filter_set_local_state($filter, $contextid, $state) {
global $DB;
// Check requested state is valid.
if (!in_array($state, array(TEXTFILTER_ON, TEXTFILTER_OFF, TEXTFILTER_INHERIT))) {
throw new coding_exception("Illegal option '$state' passed to filter_set_local_state. " .
"Must be one of TEXTFILTER_ON, TEXTFILTER_OFF or TEXTFILTER_INHERIT.");
}
if ($contextid == get_context_instance(CONTEXT_SYSTEM)->id) {
throw new coding_exception('You cannot use filter_set_local_state ' .
'with $contextid equal to the system context id.');
}
if ($state == TEXTFILTER_INHERIT) {
$DB->delete_records('filter_active', array('filter' => $filter, 'contextid' => $contextid));
return;
}
$rec = $DB->get_record('filter_active', array('filter' => $filter, 'contextid' => $contextid));
$insert = false;
if (empty($rec)) {
$insert = true;
$rec = new stdClass;
$rec->filter = $filter;
$rec->contextid = $contextid;
}
$rec->active = $state;
if ($insert) {
$DB->insert_record('filter_active', $rec);
} else {
$DB->update_record('filter_active', $rec);
}
}
/**
* Set a particular local config variable for a filter in a context.
*
* @global object
* @param string $filter The filter name, for example 'filter/tex' or 'mod/glossary'.
* @param integer $contextid The id of the context to get the local config for.
* @param string $name the setting name.
* @param string $value the corresponding value.
*/
function filter_set_local_config($filter, $contextid, $name, $value) {
global $DB;
$rec = $DB->get_record('filter_config', array('filter' => $filter, 'contextid' => $contextid, 'name' => $name));
$insert = false;
if (empty($rec)) {
$insert = true;
$rec = new stdClass;
$rec->filter = $filter;
$rec->contextid = $contextid;
$rec->name = $name;
}
$rec->value = $value;
if ($insert) {
$DB->insert_record('filter_config', $rec);
} else {
$DB->update_record('filter_config', $rec);
}
}
/**
* Remove a particular local config variable for a filter in a context.
*
* @global object
* @param string $filter The filter name, for example 'filter/tex' or 'mod/glossary'.
* @param integer $contextid The id of the context to get the local config for.
* @param string $name the setting name.
*/
function filter_unset_local_config($filter, $contextid, $name) {
global $DB;
$DB->delete_records('filter_config', array('filter' => $filter, 'contextid' => $contextid, 'name' => $name));
}
/**
* Get local config variables for a filter in a context. Normally (when your
* filter is running) you don't need to call this, becuase the config is fetched
* for you automatically. You only need this, for example, when you are getting
* the config so you can show the user an editing from.
*
* @global object
* @param string $filter The filter name, for example 'filter/tex' or 'mod/glossary'.
* @param integer $contextid The ID of the context to get the local config for.
* @return array of name => value pairs.
*/
function filter_get_local_config($filter, $contextid) {
global $DB;
return $DB->get_records_menu('filter_config', array('filter' => $filter, 'contextid' => $contextid), '', 'name,value');
}
/**
* This function is for use by backup. Gets all the filter information specific
* to one context.
*
* @global object
* @param int $contextid
* @return array Array with two elements. The first element is an array of objects with
* fields filter and active. These come from the filter_active table. The
* second element is an array of objects with fields filter, name and value
* from the filter_config table.
*/
function filter_get_all_local_settings($contextid) {
global $DB;
$context = get_context_instance(CONTEXT_SYSTEM);
return array(
$DB->get_records('filter_active', array('contextid' => $contextid), 'filter', 'filter,active'),
$DB->get_records('filter_config', array('contextid' => $contextid), 'filter,name', 'filter,name,value'),
);
}
/**
* Get the list of active filters, in the order that they should be used
* for a particular context, along with any local configuration variables.
*
* @global object
* @param object $context a context
* @return array an array where the keys are the filter names, for example
* 'filter/tex' or 'mod/glossary' and the values are any local
* configuration for that filter, as an array of name => value pairs
* from the filter_config table. In a lot of cases, this will be an
* empty array. So, an example return value for this function might be
* array('filter/tex' => array(), 'mod/glossary' => array('glossaryid', 123))
*/
function filter_get_active_in_context($context) {
global $DB;
$contextids = str_replace('/', ',', trim($context->path, '/'));
// The following SQL is tricky. It is explained on
// http://docs.moodle.org/en/Development:Filter_enable/disable_by_context
$sql = "SELECT active.filter, fc.name, fc.value
FROM (SELECT f.filter, MAX(f.sortorder) AS sortorder
FROM {filter_active} f
JOIN {context} ctx ON f.contextid = ctx.id
WHERE ctx.id IN ($contextids)
GROUP BY filter
HAVING MAX(f.active * " . $DB->sql_cast_2signed('ctx.depth') .
") > -MIN(f.active * " . $DB->sql_cast_2signed('ctx.depth') . ")
) active
LEFT JOIN {filter_config} fc ON fc.filter = active.filter AND fc.contextid = $context->id
ORDER BY active.sortorder";
$rs = $DB->get_recordset_sql($sql);
// Masssage the data into the specified format to return.
$filters = array();
foreach ($rs as $row) {
if (!isset($filters[$row->filter])) {
$filters[$row->filter] = array();
}
if (!is_null($row->name)) {
$filters[$row->filter][$row->name] = $row->value;
}
}
$rs->close();
return $filters;
}
/**
* List all of the filters that are available in this context, and what the
* local and inherited states of that filter are.
*
* @global object
* @param object $context a context that is not the system context.
* @return array an array with filter names, for example 'filter/tex' or
* 'mod/glossary' as keys. and and the values are objects with fields:
* ->filter filter name, same as the key.
* ->localstate TEXTFILTER_ON/OFF/INHERIT
* ->inheritedstate TEXTFILTER_ON/OFF - the state that will be used if localstate is set to TEXTFILTER_INHERIT.
*/
function filter_get_available_in_context($context) {
global $DB;
// The complex logic is working out the active state in the parent context,
// so strip the current context from the list.
$contextids = explode('/', trim($context->path, '/'));
array_pop($contextids);
$contextids = implode(',', $contextids);
if (empty($contextids)) {
throw new coding_exception('filter_get_available_in_context cannot be called with the system context.');
}
// The following SQL is tricky, in the same way at the SQL in filter_get_active_in_context.
$sql = "SELECT parent_states.filter,
CASE WHEN fa.active IS NULL THEN " . TEXTFILTER_INHERIT . "
ELSE fa.active END AS localstate,
parent_states.inheritedstate
FROM (SELECT f.filter, MAX(f.sortorder) AS sortorder,
CASE WHEN MAX(f.active * " . $DB->sql_cast_2signed('ctx.depth') .
") > -MIN(f.active * " . $DB->sql_cast_2signed('ctx.depth') . ") THEN " . TEXTFILTER_ON . "
ELSE " . TEXTFILTER_OFF . " END AS inheritedstate
FROM {filter_active} f
JOIN {context} ctx ON f.contextid = ctx.id
WHERE ctx.id IN ($contextids)
GROUP BY f.filter
HAVING MIN(f.active) > " . TEXTFILTER_DISABLED . "
) parent_states
LEFT JOIN {filter_active} fa ON fa.filter = parent_states.filter AND fa.contextid = $context->id
ORDER BY parent_states.sortorder";
return $DB->get_records_sql($sql);
}
/**
* This function is for use by the filter administration page.
*
* @global object
* @return array 'filtername' => object with fields 'filter' (=filtername), 'active' and 'sortorder'
*/
function filter_get_global_states() {
global $DB;
$context = get_context_instance(CONTEXT_SYSTEM);
return $DB->get_records('filter_active', array('contextid' => $context->id), 'sortorder', 'filter,active,sortorder');
}
/**
* Delete all the data in the database relating to a filter, prior to deleting it.
*
* @global object
* @param string $filter The filter name, for example 'filter/tex' or 'mod/glossary'.
*/
function filter_delete_all_for_filter($filter) {
global $DB;
if (substr($filter, 0, 7) == 'filter/') {
unset_all_config_for_plugin('filter_' . basename($filter));
}
$DB->delete_records('filter_active', array('filter' => $filter));
$DB->delete_records('filter_config', array('filter' => $filter));
}
/**
* Delete all the data in the database relating to a context, used when contexts are deleted.
*
* @param integer $contextid The id of the context being deleted.
*/
function filter_delete_all_for_context($contextid) {
global $DB;
$DB->delete_records('filter_active', array('contextid' => $contextid));
$DB->delete_records('filter_config', array('contextid' => $contextid));
}
/**
* Does this filter have a global settings page in the admin tree?
* (The settings page for a filter must be called, for example,
* filtersettingfiltertex or filtersettingmodglossay.)
*
* @param string $filter The filter name, for example 'filter/tex' or 'mod/glossary'.
* @return boolean Whether there should be a 'Settings' link on the config page.
*/
function filter_has_global_settings($filter) {
global $CFG;
$settingspath = $CFG->dirroot . '/' . $filter . '/filtersettings.php';
return is_readable($settingspath);
}
/**
* Does this filter have local (per-context) settings?
*
* @param string $filter The filter name, for example 'filter/tex' or 'mod/glossary'.
* @return boolean Whether there should be a 'Settings' link on the manage filters in context page.
*/
function filter_has_local_settings($filter) {
global $CFG;
$settingspath = $CFG->dirroot . '/' . $filter . '/filterlocalsettings.php';
return is_readable($settingspath);
}
/**
* Certain types of context (block and user) may not have local filter settings.
* the function checks a context to see whether it may have local config.
*
* @param object $context a context.
* @return boolean whether this context may have local filter settings.
*/
function filter_context_may_have_filter_settings($context) {
return $context->contextlevel != CONTEXT_BLOCK && $context->contextlevel != CONTEXT_USER;
}
/**
* Process phrases intelligently found within a HTML text (such as adding links)
*
* @staticvar array $usedpharses
* @param string $text the text that we are filtering
* @param array $link_array an array of filterobjects
* @param array $ignoretagsopen an array of opening tags that we should ignore while filtering
* @param array $ignoretagsclose an array of corresponding closing tags
* @return string
**/
function filter_phrases($text, &$link_array, $ignoretagsopen=NULL, $ignoretagsclose=NULL) {
global $CFG;
static $usedphrases;
$ignoretags = array(); //To store all the enclosig tags to be completely ignored
$tags = array(); //To store all the simple tags to be ignored
/// A list of open/close tags that we should not replace within
/// No reason why you can't put full preg expressions in here too
/// eg '<script(.+?)>' to match any type of script tag
$filterignoretagsopen = array('<head>' , '<nolink>' , '<span class="nolink">');
$filterignoretagsclose = array('</head>', '</nolink>', '</span>');
/// Invalid prefixes and suffixes for the fullmatch searches
/// Every "word" character, but the underscore, is a invalid suffix or prefix.
/// (nice to use this because it includes national characters (accents...) as word characters.
$filterinvalidprefixes = '([^\W_])';
$filterinvalidsuffixes = '([^\W_])';
/// Add the user defined ignore tags to the default list
/// Unless specified otherwise, we will not replace within <a></a> tags
if ( $ignoretagsopen === NULL ) {
//$ignoretagsopen = array('<a(.+?)>');
$ignoretagsopen = array('<a\s[^>]+?>');
$ignoretagsclose = array('</a>');
}
if ( is_array($ignoretagsopen) ) {
foreach ($ignoretagsopen as $open) $filterignoretagsopen[] = $open;
foreach ($ignoretagsclose as $close) $filterignoretagsclose[] = $close;
}
//// Double up some magic chars to avoid "accidental matches"
$text = preg_replace('/([#*%])/','\1\1',$text);
////Remove everything enclosed by the ignore tags from $text
filter_save_ignore_tags($text,$filterignoretagsopen,$filterignoretagsclose,$ignoretags);
/// Remove tags from $text
filter_save_tags($text,$tags);
/// Time to cycle through each phrase to be linked
$size = sizeof($link_array);
for ($n=0; $n < $size; $n++) {
$linkobject =& $link_array[$n];
/// Set some defaults if certain properties are missing
/// Properties may be missing if the filterobject class has not been used to construct the object
if (empty($linkobject->phrase)) {
continue;
}
/// Avoid integers < 1000 to be linked. See bug 1446.
$intcurrent = intval($linkobject->phrase);
if (!empty($intcurrent) && strval($intcurrent) == $linkobject->phrase && $intcurrent < 1000) {
continue;
}
/// All this work has to be done ONLY it it hasn't been done before
if (!$linkobject->work_calculated) {
if (!isset($linkobject->hreftagbegin) or !isset($linkobject->hreftagend)) {
$linkobject->work_hreftagbegin = '<span class="highlight"';
$linkobject->work_hreftagend = '</span>';
} else {
$linkobject->work_hreftagbegin = $linkobject->hreftagbegin;
$linkobject->work_hreftagend = $linkobject->hreftagend;
}
/// Double up chars to protect true duplicates
/// be cleared up before returning to the user.
$linkobject->work_hreftagbegin = preg_replace('/([#*%])/','\1\1',$linkobject->work_hreftagbegin);
if (empty($linkobject->casesensitive)) {
$linkobject->work_casesensitive = false;
} else {
$linkobject->work_casesensitive = true;
}
if (empty($linkobject->fullmatch)) {
$linkobject->work_fullmatch = false;
} else {
$linkobject->work_fullmatch = true;
}
/// Strip tags out of the phrase
$linkobject->work_phrase = strip_tags($linkobject->phrase);
/// Double up chars that might cause a false match -- the duplicates will
/// be cleared up before returning to the user.
$linkobject->work_phrase = preg_replace('/([#*%])/','\1\1',$linkobject->work_phrase);
/// Set the replacement phrase properly
if ($linkobject->replacementphrase) { //We have specified a replacement phrase
/// Strip tags
$linkobject->work_replacementphrase = strip_tags($linkobject->replacementphrase);
} else { //The replacement is the original phrase as matched below
$linkobject->work_replacementphrase = '$1';
}
/// Quote any regular expression characters and the delimiter in the work phrase to be searched
$linkobject->work_phrase = preg_quote($linkobject->work_phrase, '/');
/// Work calculated
$linkobject->work_calculated = true;
}
/// If $CFG->filtermatchoneperpage, avoid previously (request) linked phrases
if (!empty($CFG->filtermatchoneperpage)) {
if (!empty($usedphrases) && in_array($linkobject->work_phrase,$usedphrases)) {
continue;
}
}
/// Regular expression modifiers
$modifiers = ($linkobject->work_casesensitive) ? 's' : 'isu'; // works in unicode mode!
/// Do we need to do a fullmatch?
/// If yes then go through and remove any non full matching entries
if ($linkobject->work_fullmatch) {
$notfullmatches = array();
$regexp = '/'.$filterinvalidprefixes.'('.$linkobject->work_phrase.')|('.$linkobject->work_phrase.')'.$filterinvalidsuffixes.'/'.$modifiers;
preg_match_all($regexp,$text,$list_of_notfullmatches);
if ($list_of_notfullmatches) {
foreach (array_unique($list_of_notfullmatches[0]) as $key=>$value) {
$notfullmatches['<*'.$key.'*>'] = $value;
}
if (!empty($notfullmatches)) {
$text = str_replace($notfullmatches,array_keys($notfullmatches),$text);
}
}
}
/// Finally we do our highlighting
if (!empty($CFG->filtermatchonepertext) || !empty($CFG->filtermatchoneperpage)) {
$resulttext = preg_replace('/('.$linkobject->work_phrase.')/'.$modifiers,
$linkobject->work_hreftagbegin.
$linkobject->work_replacementphrase.
$linkobject->work_hreftagend, $text, 1);
} else {
$resulttext = preg_replace('/('.$linkobject->work_phrase.')/'.$modifiers,
$linkobject->work_hreftagbegin.
$linkobject->work_replacementphrase.
$linkobject->work_hreftagend, $text);
}
/// If the text has changed we have to look for links again
if ($resulttext != $text) {
/// Set $text to $resulttext
$text = $resulttext;
/// Remove everything enclosed by the ignore tags from $text
filter_save_ignore_tags($text,$filterignoretagsopen,$filterignoretagsclose,$ignoretags);
/// Remove tags from $text
filter_save_tags($text,$tags);
/// If $CFG->filtermatchoneperpage, save linked phrases to request
if (!empty($CFG->filtermatchoneperpage)) {
$usedphrases[] = $linkobject->work_phrase;
}
}
/// Replace the not full matches before cycling to next link object
if (!empty($notfullmatches)) {
$text = str_replace(array_keys($notfullmatches),$notfullmatches,$text);
unset($notfullmatches);
}
}
/// Rebuild the text with all the excluded areas
if (!empty($tags)) {
$text = str_replace(array_keys($tags), $tags, $text);
}
if (!empty($ignoretags)) {
$ignoretags = array_reverse($ignoretags); /// Reversed so "progressive" str_replace() will solve some nesting problems.
$text = str_replace(array_keys($ignoretags),$ignoretags,$text);
}
//// Remove the protective doubleups
$text = preg_replace('/([#*%])(\1)/','\1',$text);
/// Add missing javascript for popus
$text = filter_add_javascript($text);
return $text;
}
/**
* @todo Document this function
* @param array $linkarray
* @return array
*/
function filter_remove_duplicates($linkarray) {
$concepts = array(); // keep a record of concepts as we cycle through
$lconcepts = array(); // a lower case version for case insensitive
$cleanlinks = array();
foreach ($linkarray as $key=>$filterobject) {
if ($filterobject->casesensitive) {
$exists = in_array($filterobject->phrase, $concepts);
} else {
$exists = in_array(moodle_strtolower($filterobject->phrase), $lconcepts);
}
if (!$exists) {
$cleanlinks[] = $filterobject;
$concepts[] = $filterobject->phrase;
$lconcepts[] = moodle_strtolower($filterobject->phrase);
}
}
return $cleanlinks;
}
/**
* Extract open/lose tags and their contents to avoid being processed by filters.
* Useful to extract pieces of code like <a>...</a> tags. It returns the text
* converted with some <#xTEXTFILTER_EXCL_SEPARATORx#> codes replacing the extracted text. Such extracted
* texts are returned in the ignoretags array (as values), with codes as keys.
*
* @param string $text the text that we are filtering (in/out)
* @param array $filterignoretagsopen an array of open tags to start searching
* @param array $filterignoretagsclose an array of close tags to end searching
* @param array $ignoretags an array of saved strings useful to rebuild the original text (in/out)
**/
function filter_save_ignore_tags(&$text, $filterignoretagsopen, $filterignoretagsclose, &$ignoretags) {
/// Remove everything enclosed by the ignore tags from $text
foreach ($filterignoretagsopen as $ikey=>$opentag) {
$closetag = $filterignoretagsclose[$ikey];
/// form regular expression
$opentag = str_replace('/','\/',$opentag); // delimit forward slashes
$closetag = str_replace('/','\/',$closetag); // delimit forward slashes
$pregexp = '/'.$opentag.'(.*?)'.$closetag.'/is';
preg_match_all($pregexp, $text, $list_of_ignores);
foreach (array_unique($list_of_ignores[0]) as $key=>$value) {
$prefix = (string)(count($ignoretags) + 1);
$ignoretags['<#'.$prefix.TEXTFILTER_EXCL_SEPARATOR.$key.'#>'] = $value;
}
if (!empty($ignoretags)) {
$text = str_replace($ignoretags,array_keys($ignoretags),$text);
}
}
}
/**
* Extract tags (any text enclosed by < and > to avoid being processed by filters.
* It returns the text converted with some <%xTEXTFILTER_EXCL_SEPARATORx%> codes replacing the extracted text. Such extracted
* texts are returned in the tags array (as values), with codes as keys.
*
* @param string $text the text that we are filtering (in/out)
* @param array $tags an array of saved strings useful to rebuild the original text (in/out)
**/
function filter_save_tags(&$text, &$tags) {
preg_match_all('/<([^#%*].*?)>/is',$text,$list_of_newtags);
foreach (array_unique($list_of_newtags[0]) as $ntkey=>$value) {
$prefix = (string)(count($tags) + 1);
$tags['<%'.$prefix.TEXTFILTER_EXCL_SEPARATOR.$ntkey.'%>'] = $value;
}
if (!empty($tags)) {
$text = str_replace($tags,array_keys($tags),$text);
}
}
/**
* Add missing openpopup javascript to HTML files.
*
* @param string $text
* @return string
*/
function filter_add_javascript($text) {
global $CFG;
if (stripos($text, '</html>') === FALSE) {
return $text; // this is not a html file
}
if (strpos($text, 'onclick="return openpopup') === FALSE) {
return $text; // no popup - no need to add javascript
}
$js ="
<script type=\"text/javascript\">
<!--
function openpopup(url,name,options,fullscreen) {
fullurl = \"".$CFG->httpswwwroot."\" + url;
windowobj = window.open(fullurl,name,options);
if (fullscreen) {
windowobj.moveTo(0,0);
windowobj.resizeTo(screen.availWidth,screen.availHeight);
}
windowobj.focus();
return false;
}
// -->
</script>";
if (stripos($text, '</head>') !== FALSE) {
//try to add it into the head element
$text = str_ireplace('</head>', $js.'</head>', $text);
return $text;
}
//last chance - try adding head element
return preg_replace("/<html.*?>/is", "\\0<head>".$js.'</head>', $text);
}
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